ITN6 Instructor Materials Chapter2

Chapter 2: Configure a Network Operating System Introduction to Networks v6.0 Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Chapter - Sections & Objectives  2.1 IOS Bootcamp • Explain the purpose of Cisco IOS • Explain how to access a Cisco IOS device for configuration purposes • Explain how to navigate Cisco IOS to configure network devices • Describe the command structure of Cisco IOS software  2.2 Basic Device Configuration • Configure hostnames on a Cisco IOS device using the CLI • Use Cisco IOS commands to limit access to device configurations • Use IOS commands to save the running configuration  2.3 Address Schemes • Explain how devices communicate across network media • Configure a host device with an IP address • Verify connectivity between two end devices Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 2.1 IOS Bootcamp Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential IOS Bootcamp Cisco IOS  Operating Systems • PC OS allows users to interact with the computer • User-computer interaction in PC OSs are often done via mouse, keyboard and monitor • Cisco IOS is also an Operating System • Cisco IOS allows users to interact with Cisco devices  Cisco IOS enables a technician to: • Use a keyboard to run CLI-based network programs • Use a keyboard to enter text and text-based commands • View output on a monitor  All Cisco networking devices come with a default IOS  It is possible to upgrade the IOS version or feature set Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential IOS Bootcamp Cisco IOS Access  Access Methods • Console • Auxiliar • Virtual Terminal (Telnet / SSH)  Terminal Emulation Programs • PuTTY • Tera Term • SecureCRT Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential IOS Bootcamp Navigate the IOS  Cisco IOS Modes of Operation • Initial configuration must be done via console connection • Configuration is then done via various CLI command modes  Primary Command Modes • User EXEC Mode • Privileged EXEC Mode  Configuration Command Modes • The Configure Terminal command enters the Global Configuration Mode • Sub-configuration modes are accessible from the Privileged EXEC Mode • Examples are: swtich(config-line)# and switch(config-if)#  Navigate Between IOS Modes • Navigation between modes is also done via commands • The enable command enters the Privileged EXEC Mode • The exit commands exits to the parent command mode Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential IOS Bootcamp The Command Structure  Basic IOS Command Structure • The general syntax for a command is the command followed by any appropriate keywords and arguments • Keyword - a specific parameter defined in the operating system • Argument - not predefined; a value or variable defined by the user  IOS Command Syntax • Provides the pattern or format that must be used when entering a command • The Cisco IOS Command Reference is the ultimate source of information for a particular IOS command  IOS Help Feature • The IOS has two forms of help available: Context-Sensitive Help and Command Syntax Check  Hotkeys and Shortcuts • Commands and keywords can be shortened to the minimum number of characters that identify a unique selection • Line editing keyboard shortcuts such as Ctrl-A are also supported Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 2.2 Basic Device Configuration Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Basic Device Configuration Hostnames  Device Names • Hostnames allow devices to be identified by network administrators over a network or the Internet • Very important and should also be displayed in the topology  Configure Hostnames • IOS hostnames should: • Start with a letter • Contain no spaces • End with letter or digit • Use only letters, digits or dashes • Be less than 64 characters in length Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Basic Device Configuration Limit Access to Device Configurations  Secure Device Access • Secure privileged EXEC and user EXEC access with a password • Secure virtual terminal lines with a password  Configure Passwords • Use strong passwords • Avoid re-using passwords  Encrypt Passwords • Cisco IOS displays passwords in plain text by default • Passwords should be encrypted  Banner Messages • Important part of the legal process in the event that someone is prosecuted for breaking into a device • Wording that implies that a login is "welcome" or "invited" is not appropriate • Often used for legal notification because it is displayed to all connected terminals Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 10 Basic Device Configuration Save Configurations  Save the Running Configuration File • File stored in NVRAM that contains all of the commands that will be used upon startup or reboot • NVRAM does not lose its contents when the device is powered off  Alter the Running Configuration • File stored in RAM that reflects the current configuration, modifying affects the operation of a Cisco device immediately • RAM loses all of its content when the device is powered off or restarted  Capture Configuration to a Text File • Configuration files can also be saved and archived to a text document • The configuration can then be edited with any text editor and placed back in the device Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 11 2.3 Address Schemes Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 12 Address Schemes Ports and Addresses  IP Addresses • Each end device on a network must be configured with an IP address • Enable devices to establish end-to-end communication on the Internet • The structure of an IPv4 address is called dotted decimal notation and is represented by four decimal numbers between and 255 • IPv6 is the most recent version of IP and the replacement for the more common IPv4  Interface and Ports • Network communications depend on interfaces and the cables that connect them • Different types of network media have different features and benefits • Ethernet is the most common local area network (LAN) technology • SVI provides a means to remotely manage a switch over a network Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 13 Address Schemes Configure IP Addressing  Manual IP Address Configuration for End Devices • To manually configure an IPv4 address on a Windows host, open the Control Panel > Network Sharing Center > Change adapter settings and choose the adapter • Next right-click and select Properties to display the Local Area Connection Properties shown in Figure  Automatic IP Address Configuration for End Devices • DHCP enables automatic IPv4 address configuration for every end device that has DHCP enabled No extra configuration is needed  Switch Virtual Interface Configuration • To configure an SVI on a switch, use the interface vlan global configuration command Vlan is not an actual physical interface but a virtual one Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 14 Address Schemes Verifying Connectivity  Interface Addressing Verification • Cisco IOS supports commands to allow IP configuration verification  End-To-End Connectivity Test • The ping command can be used to test connectivity to another device on the network or a website on the Internet Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 15 2.4 Chapter Summary Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 16 Chapter Summary Summary  Explain the features and functions of Cisco IOS Software  Configure initial settings on a network device using the Cisco IOS software  Given an IP addressing scheme, configure IP address parameters on end devices to provide end-to-end connectivity in a small to medium-sized business network Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 17